Upregulation of urokinase in alveolar macrophages and lung tissue in response to silica particles.

Impaired fibrinolytic activity and persistent fibrin deposits in lung tissue have been associated with lung fibrotic disorders. The present study examined the sources of plaminogen activator (PA) changes induced by a single intratracheal administration of silica particles (5 mg) in the mouse lung. We found in both control and silica-treated animals that amiloride almost totally abolished PA activity in bronchoalveolar lavage (BAL) fluid (BALF), indicating that initial upregulation (from day 1) as well as sustained PA activity (up to day 30) observed in response to silica is related to changes in urokinase-type PA (uPA). The upregulation of BALF uPA activity was associated with a marked and persistent increase in uPA mRNA levels in lung tissue. Changes in uPA expression were also reflected in the BAL cell fraction. A maximal and constant increase in cell uPA activity was associated with the early response to silica, whereas significant but lower upregulation was still noted at the fibrotic stage. From days 3 to 30, a progressive increase in uPA mRNA levels was noted in BAL inflammatory cells elicited by silica. Because the number of BAL neutrophils was strongly correlated with BALF and BAL cell-associated uPA activity, their involvement in uPA upregulation was addressed by inducing neutropenia with cyclophosphamide (200 mg/kg ip) before administration of the silica. Neutrophilic depletion did not, however, reduce, and even increased, the BAL cell-associated uPA activity. At the BALF level, neutropenia did not change PA activity in silica-treated mice, pointing to alveolar macrophages as the principal source of uPA in response to silica. Immunohistochemical stainings identified alveolar macrophages and pneumocytes as uPA-expressing cells in silica-treated animals (day 30). Intense and heterogenous staining was observed in silicotic nodules. These findings indicate that urokinase produced by alveolar macrophages is operative not only at the alveolitis stage but also later in the fibrotic process, produced by silica particles, supporting the role of uPA in fibrogenesis

[Internal Carotid-artery Occlusion Due To a Vagal Paraganglioma]

A 72 year-old-man presented with right hemiparesis and global aphasia related to a large infarct in the left middle cerebral artery territory. A left carotid angiography revealed internal carotid artery occlusion and vascular blush just below the base of the skull The blush was supplied by branches from the external carotid artery. Cervical CT-scan showed a large tumor centered by the left internal carotid artery. At cervical surgery, the internal carotid artery was compressed and infiltrated by the tumoral process : a benign paraganglioma The site below the base of the skull and the connection between tumor and vagal nerve suggested a vagal paraganglioma. To our knowledge, this is the first case of cerebral infarction and internal carotid artery occlusion revealing a vagal paraganglioma

Occlusion carotidienne par un paragangliome vagal.

A 72 year-old-man presented with right hemiparesis and global aphasia related to a large infarct in the left middle cerebral artery territory. A left carotid angiography revealed internal carotid artery occlusion and vascular blush just below the base of the skull. The blush was supplied by branches from the external carotid artery. Cervical CT-scan showed a large tumor centered by the left internal carotid artery. At cervical surgery, the internal carotid artery was compressed and infiltrated by the tumoral process: a benign paraganglioma. The site below the base of the skull and the connection between tumor and vagal nerve suggested a vagal paraganglioma. To our knowledge, this is the first case of cerebral infarction and internal carotid artery occlusion revealing a vagal paraganglioma

Kyste arthro-synovial de hanche sur prothèse totale à couple de friction céramique-céramique

An inguinal arthrosynovial cyst of the hip joint developed after total hip arthroplasty leading to compression of the femoral vein. This complication occurred after implantation of a non-cemented prosthesis with a ceramic-on-ceramic interface inserted in a polyethylene sandwich. Multiple foreign bodies composed of both ceramic and polyethylene particles were visualized microscopically. Later, rupture of the joint interface required implant replacement. This cyst was a precursor sign of a deteriorating prosthesis surface

Exudative lesions of Reinke's space. An anatomopathological correlation.

Few anatomopathological criteria for distinguishing vocal nodules, polyps or REINKE's edema have been established in previously published studies. In order to study this issue, 163 samples (from 119 patients) were examined by an experienced anatomopathologist, without her prior knowledge of the macroscopic or microscopic diagnosis. In all the cases, the presence of exudative phenomena in REINKE's space proved to be the determining factors, with four outstanding stages of evolution: edema, fibrosis, deposits of fibrin and development of vascular ectasia. Although each of the three entities were seen to have their specific characteristics, a large number of lesions showed histological features which were not very specific, and were dominated by edema. Furthermore, the coexistence of different anatomopathological features makes each group heterogeneous. We propose a model which groups all the exudative lesions of REINKE's space by insisting, on the one hand, on the evolution of the anomalies and, on the other hand, the etiological factors (vocal misuse, tobacco, alcohol acute, vocal trauma ...) which determine the onset of either one or other lesion

External auditory canal cholesteatoma

A cholesteatoma originating in the external auditory canal is a rare finding. We report 2 cases illustrating its typical localization in the inferior part of the auditory canal and its marked osteolytic character. The extension of such a cholesteatoma in the depth of the temporal bone is often larger than suggested by clinical examination. Since the purpose of treatment is to achieve the complete eradication of the epidermic matrix, surgical treatment is required in most cases. We discuss herein the follow-up strategies, keeping in mind that local recurrence and bilateral disease are not uncommon